org.apache.lucene.queries.intervals.RepeatingIntervalsSource Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.lucene.queries.intervals;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.MatchesIterator;
import org.apache.lucene.search.MatchesUtils;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryVisitor;
/**
* Generates an iterator that spans repeating instances of a sub-iterator, avoiding minimization.
* This is useful for repeated terms within an unordered interval, for example, ensuring that
* multiple iterators do not match on a single term.
*
* The generated iterators have a specialized {@link IntervalIterator#width()} implementation
* that sums up the widths of the individual sub-iterators, rather than just returning the full span
* of the iterator.
*/
class RepeatingIntervalsSource extends IntervalsSource {
static IntervalsSource build(IntervalsSource in, int childCount) {
if (childCount == 1) {
return in;
}
assert childCount > 0;
return new RepeatingIntervalsSource(in, childCount);
}
final IntervalsSource in;
final int childCount;
String name;
private RepeatingIntervalsSource(IntervalsSource in, int childCount) {
this.in = in;
this.childCount = childCount;
}
public void setName(String name) {
this.name = name;
}
@Override
public IntervalIterator intervals(String field, LeafReaderContext ctx) throws IOException {
IntervalIterator it = in.intervals(field, ctx);
if (it == null) {
return null;
}
return new DuplicateIntervalIterator(it, childCount);
}
@Override
public IntervalMatchesIterator matches(String field, LeafReaderContext ctx, int doc)
throws IOException {
List subs = new ArrayList<>();
for (int i = 0; i < childCount; i++) {
IntervalMatchesIterator mi = in.matches(field, ctx, doc);
if (mi == null) {
return null;
}
subs.add(mi);
}
return DuplicateMatchesIterator.build(subs);
}
@Override
public void visit(String field, QueryVisitor visitor) {
in.visit(field, visitor);
}
@Override
public int minExtent() {
return in.minExtent();
}
@Override
public Collection pullUpDisjunctions() {
return Collections.singleton(this);
}
@Override
public int hashCode() {
return Objects.hash(in, childCount);
}
@Override
public boolean equals(Object other) {
if (other instanceof RepeatingIntervalsSource == false) return false;
RepeatingIntervalsSource o = (RepeatingIntervalsSource) other;
return Objects.equals(this.in, o.in) && this.childCount == o.childCount;
}
@Override
public String toString() {
String s = in.toString();
StringBuilder out = new StringBuilder(s);
for (int i = 1; i < childCount; i++) {
out.append(",").append(s);
}
if (name != null) {
return name + "(" + out.toString() + ")";
}
return out.toString();
}
private static class DuplicateIntervalIterator extends IntervalIterator {
private final IntervalIterator in;
final int[] cache;
final int cacheLength;
int cacheBase;
boolean started = false;
boolean exhausted = false;
private DuplicateIntervalIterator(IntervalIterator primary, int copies) {
this.in = primary;
this.cacheLength = copies;
this.cache = new int[this.cacheLength * 2];
}
@Override
public int start() {
return exhausted ? NO_MORE_INTERVALS : cache[(cacheBase % cacheLength) * 2];
}
@Override
public int end() {
return exhausted
? NO_MORE_INTERVALS
: cache[(((cacheBase + cacheLength - 1) % cacheLength) * 2) + 1];
}
@Override
public int width() {
int width = 0;
for (int i = 0; i < cacheLength; i++) {
int pos = (cacheBase + i) % cacheLength;
width += cache[pos * 2] - cache[pos * 2 + 1] + 1;
}
return width;
}
@Override
public int gaps() {
return super.width() - width();
}
@Override
public int nextInterval() throws IOException {
if (exhausted) {
return NO_MORE_INTERVALS;
}
if (started == false) {
for (int i = 0; i < cacheLength; i++) {
if (cacheNextInterval(i) == NO_MORE_INTERVALS) {
return NO_MORE_INTERVALS;
}
}
cacheBase = 0;
started = true;
return start();
} else {
int insert = (cacheBase + cacheLength) % cacheLength;
cacheBase = (cacheBase + 1) % cacheLength;
return cacheNextInterval(insert);
}
}
private int cacheNextInterval(int linePos) throws IOException {
if (in.nextInterval() == NO_MORE_INTERVALS) {
exhausted = true;
return NO_MORE_INTERVALS;
}
cache[linePos * 2] = in.start();
cache[linePos * 2 + 1] = in.end();
return start();
}
@Override
public float matchCost() {
return in.matchCost();
}
@Override
public int docID() {
return in.docID();
}
@Override
public int nextDoc() throws IOException {
started = exhausted = false;
Arrays.fill(cache, -1);
return in.nextDoc();
}
@Override
public int advance(int target) throws IOException {
started = exhausted = false;
Arrays.fill(cache, -1);
return in.advance(target);
}
@Override
public long cost() {
return in.cost();
}
}
private static class DuplicateMatchesIterator implements IntervalMatchesIterator {
List subs;
boolean cached = false;
static IntervalMatchesIterator build(List subs) throws IOException {
int count = subs.size();
while (count > 0) {
for (int i = 0; i < count; i++) {
if (subs.get(count - 1).next() == false) {
return null;
}
}
count--;
}
return new DuplicateMatchesIterator(subs);
}
private DuplicateMatchesIterator(List subs) throws IOException {
this.subs = subs;
}
@Override
public boolean next() throws IOException {
if (cached == false) {
return cached = true;
}
if (subs.get(subs.size() - 1).next() == false) {
return false;
}
for (int i = 0; i < subs.size() - 1; i++) {
subs.get(i).next();
}
return true;
}
@Override
public int startPosition() {
return subs.get(0).startPosition();
}
@Override
public int endPosition() {
return subs.get(subs.size() - 1).endPosition();
}
@Override
public int startOffset() throws IOException {
return subs.get(0).startOffset();
}
@Override
public int endOffset() throws IOException {
return subs.get(subs.size() - 1).endOffset();
}
@Override
public MatchesIterator getSubMatches() throws IOException {
List subMatches = new ArrayList<>();
for (MatchesIterator mi : subs) {
MatchesIterator sub = mi.getSubMatches();
if (sub == null) {
sub = new ConjunctionMatchesIterator.SingletonMatchesIterator(mi);
}
subMatches.add(sub);
}
return MatchesUtils.disjunction(subMatches);
}
@Override
public Query getQuery() {
throw new UnsupportedOperationException();
}
@Override
public int gaps() {
int width = endPosition() - startPosition() + 1;
for (MatchesIterator mi : subs) {
width = width - (mi.endPosition() - mi.startPosition() + 1);
}
return width;
}
@Override
public int width() {
int width = 0;
for (MatchesIterator mi : subs) {
width += (mi.endPosition() - mi.startPosition() + 1);
}
return width;
}
}
}